While looking at a Zeiss Terra 3-9 got to compare it to a Zeiss Terra 4-12 and noted that length and weight were virtually the same.

I'm interested in a 1" scope for a sporter size .223. Was going to go with a 3-9 but for what I'm doing a 4-12 in the same size (length) might get the nod.

Are there other such 'trim' 4-12 scope under $450?

The Leupold VX-II is available for around that price and is essentially the same size and weight as its 3-9X counterpart. But the Leupold VX-I will serve you fully as well and is even less expensive. I have both (as well as a couple of Leupold VX-3 4.5-14) and have never found the VX-I lacking compared to its more expensive brethren.

If you're shooting at extended yardages the LR Duplex (in either the I or the II) provides 300, 400, and 500 yard sighting references.

I can't think of a lighter trimmer scope in that power range than the Leupolds that Stonecreek recommends. Most of my hunting rifles wear Leupolds for that very reason, that and their generous eye relief and excellent customer support.

I third the leupold. The VX-I and II are great scopes. The VX-II will give you parallax adjustment on the bell.